package com.exercise.filter;

import com.alibaba.fastjson.JSON;
import com.exercise.common.BaseContext;
import com.exercise.common.R;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 拦截访问路径类，拦截未登录用户访问
 * @author 陈凯
 * @create 2023-03-06-14:29
 */

@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    private static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //放行路径
        String[] uris = new String[]{
            "/employee/login",
            "/employee/logout",
            "/backend/**",
            "/front/**",
            "/common/**",
            "/user/sendMsg",
            "/user/login",
            "/doc.html",
            "/webjars/**",
            "/swagger-resources",
            "/v2/api-docs"
        };

        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();

        //2、判断本次请求是否符合处理
        Boolean result = checkPath(uris, requestURI);

        //3、如果不需要处理则直接放行
        if (result){
            filterChain.doFilter(request, response);
            return;
        }

        //4-1、判断登录状态，如果已经登录，则直接放行
        if (request.getSession().getAttribute("employee") != null){

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2、判断登录状态，如果已经登录，则直接放行
        if (request.getSession().getAttribute("user") != null){

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request,response);
            return;
        }

        //5、如果未登录则直接返回登录界面
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次路径是否放行
     * @param uris
     * @param requestUri
     * @return
     */
    public Boolean checkPath(String[] uris, String requestUri){
        for (String uri : uris) {
            boolean match = PATH_MATCHER.match(uri, requestUri);
            if (match){
                return true;
            }
        }
        return false;
    }
}
